Manufacturers commonly package and distribute foodstuffs in assemblies that include a container, and a removable closure. These assemblies simplify the transportation of packaged foodstuffs, provide surface space for nutritional labeling, and in some instances function as the receptacle from which a user consumes the foodstuff.
The container includes a bowl portion and a removable lid. The bowl portion defines a cavity suitable to contain a quantity of dry, liquid, and/or semi-liquid product. The bowl portion typically has a generally cylindrical shape and a generally flat bottom, which stabilizes the container. The removable lid seals the cavity formed by the bowl portion to preserve the freshness of the food product and to prevent the food product from spilling out of the bowl portion.
The lid is separable from the bowl portion to expose an opening through which the user removes the product stored within the container. The removable lid may include a pull-tab or other similar device to assist a user in permanently detaching the lid from the bowl portion.
After detaching the lid, a user may place the bowl portion in a microwave oven to heat the product before consumption. Accordingly, the bowl portion may be manufactured from a microwave safe material. In general, users place the closure over the opening formed by the removal of the lid before heating the bowl portion in a microwave oven.
A chime (also referred to as a lip or a bead) surrounds the upper edge of the bowl portion and defines the opening of the container. The chime has an upper surface, a radially outer surface, a radially inner surface, and a bottom surface. The lid and the chime may be an integral structure attached to the bowl portion, or the chime may be formed integrally with the bowl portion and the lid may be removably connected to the chime. In either case, the chime remains connected to the bowl portion after the lid has been removed. In a typical product, the lid cannot be reattached to the chime after the user has separated the lid from the chime.
The closure covers the opening of the container and is configured to be removed and reattached to the container. During distribution and storage of the container and closure assembly, the closure fits over the chime and the lid. Accordingly, the closure provides a surface upon which a user may stack other container and closure assemblies.
During use, the user removes the closure from the container to expose the lid. After the user removes the lid, the closure is reattached to the container to cover the opening. The closure may include vent openings, which enable steam to escape the bowl portion during heating. Additionally, the closure prevents the food product within the bowl portion from splattering out of the container during heating. Once the contents of the container have been prepared the closure is removed so the user can consume the contents.
The closure may distort and/or deform during heating of the container filled with food and covered by the closure. In particular, during heating the closure may expand or otherwise change shape.
One example of a closure of this type is described in U.S. Pat. No. 7,687,004 (the '004 Patent), the entire disclosure of which is incorporated by reference. The closure described in the '004 Patent includes a pair of latch members on opposite sides of a skirt surrounding the upper lip of the container. The latch members are hingedly connected to the skirt so that they can be pivoted outward to disengage from the container lip. The latch members function very well to permit engagement and disengagement of the closure from the container, but the structure of the latch and hinge complicate the manufacture of the closure.
An improved container and closure assembly is desirable which includes a closure that securely attaches to its associated container under various thermal conditions, that can be readily engaged and disengaged from the container, and that can be easily manufactured.